In the manufacture of vehicles there has long been a desire to be able to manufacture bodies consisting of as few components as possible, thus enabling production to be carried out in the most rational and reasonable manner possible. At the same time there is a desire for such parts to have as much strength as possible in order to give the vehicle the required rigidity and above all safety for both passengers and surroundings. In recent years plastics materials have been increasingly employed in the manufacture of cabins or bodies for vehicles. To some extent only individual elements of plastic have been used, but the development of new and modern plastics materials, and the production processes currently available have made it possible to make relatively large plates and body parts which can be assembled according to the prior art and attached to a framework for bodies by means of methods such as riveting, screwing, gluing, etc. The weakness of the methods used to date, however, is that when plate or panel elements of this kind are of a certain size they tend to become pliable and unstable with regard to shape. Thus there has been a requirement to be able to manufacture construction parts, which by means of three-dimensional shape reduce the number of panel elements which have to be employed in the construction of a body, while at the same time this three-dimnensional shape gives the construction element the greatest possible inherent strength. By means of a design of this kind it will also be possible to achieve a weight saving since the use of a heavy and expensive framework can be avoided.
This desire to provide larger body parts with a three-dimensional shape is particularly relevant in connection with the development of small, light vehicles, especially such as those designed to be powered electrically or operated with small, light engines. Body shape parts of this kind can constitute a front part or rear part of such vehicles and as the ultimate consequence of this, it could be envisaged that the entire vehicle body could be made in one piece, where only door and window elements have to be added.